```
                         ______  __      ____  _   __  ______
                        / ____/ / /     /  _/ / | / / / ____/
                       / /     / /      / /  /  |/ / / / __
                      / /___  / /___  _/ /  / /|  / / /_/ /
                      \____/ /_____/ /___/ /_/ |_/  \____/

```


##DESCRIPTION
Cling is an interactive C++ interpreter, built on top of Clang and LLVM compiler infrastructure. Cling realizes the [read-eval-print loop (REPL)](http://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop) concept, in order to leverage rapid application development. Implemented as a small extension to LLVM and Clang, the interpreter reuses their strengths such as the praised concise and expressive compiler diagnostics.

See also the [cling web page](https://cdn.rawgit.com/root-mirror/cling/master/www/index.html)

### Further information & demos
  Please note that some of the resources are rather old and most of the stated limitations are outdated.
  * [talks](tree/master/www/docs/talks)
  * http://blog.coldflake.com/posts/2012-08-09-On-the-fly-C++.html
  * http://solarianprogrammer.com/2012/08/14/cling-cpp-11-interpreter/
  * https://www.youtube.com/watch?v=f9Xfh8pv3Fs
  * https://www.youtube.com/watch?v=BrjV1ZgYbbA
  * https://www.youtube.com/watch?v=wZZdDhf2wDw
  * https://www.youtube.com/watch?v=eoIuqLNvzFs

##INSTALLATION
###Release Notes
  See our [release notes](docs/ReleaseNotes.md) to find what's new.
###Binaries
  We offer binary snapshots for download at https://root.cern.ch/download/cling/

###Source
  CLING source depends on the [LLVM][1] and [CLANG][2] headers and libraries.
You will also need [CMake][3] >= 2.6.1 or GNU Make to build all of those
packages and [subversion][4] and [git][5] to get the source code.

   [1]: http://llvm.org
   [2]: http://clang.llvm.org
   [3]: http://cmake.org
   [4]: http://subversion.tigris.org
   [5]: http://git-scm.com

####Building
  Building LLVM and CLANG you must:
   * Check out the sources:
```bash
    git clone http://root.cern.ch/git/llvm.git src
    cd src
    git checkout cling-patches
    cd tools
    git clone http://root.cern.ch/git/cling.git
    git clone http://root.cern.ch/git/clang.git
    cd clang
    git checkout cling-patches
```
   * Configure, build and install them, either using CMake:

```bash
    cd ../../../
    mkdir build
    cd build
    cmake -DCMAKE_INSTALL_PREFIX=/some/install/dir \
          -DLLVM_TARGETS_TO_BUILD=host \
          -DCMAKE_BUILD_TYPE=Debug \
          ../src
    make
    make install
```
   * or GNU Make (see ../src/configure --help for all options):

```bash
    cd ../../../
    mkdir build
    cd build
    ../src/configure --prefix=/some/install/dir
    make
    make install
```
#####Cling Packaging Tool
Cling's tree has a user-friendly, command-line utility written in Python called
Cling Packaging Tool (CPT) which can build Cling from source and generate
installer bundles for a wide range of platforms.

If you have Cling's source cloned locally, you can find the tool in
```tools/packaging``` directory. Alternatively, you can download the script
manually, or by using ```wget```:
```sh
wget https://raw.githubusercontent.com/root-mirror/cling/master/tools/packaging/cpt.py
chmod +x cpt.py
```

Full documentation of CPT can be found in [tools/packaging](tree/master/tools/packaging).

##USAGE
```c++
/some/install/dir/bin/cling '#include <stdio.h>' 'printf("Hello World!\n")'`
```

To get started run:
```bash
/some/install/dir/bin/cling --help`
```
or type
```
/some/install/dir/bin/cling
[cling]$ .help`
```

## Jupyter

cling comes with a [Jupyter][6] kernel. After building cling, install Jupyter and run ```jupyter kernelspec install cling```. It requires a fairly new Jupyter. Make sure cling is in your PATH when you start jupyter!

See also the [tools/Jupyter/kernel](tree/master/tools/Jupyter/kernel) subdirectory.

   [6]: http://jupyter.org

##DEVELOPERS' CORNER
   We have doxygen documentation of cling's code at: http://cling.web.cern.ch/cling/doxygen/

###CONTRIBUTIONS
  Every contribution is very welcome. It is considered as a donation and its copyright and any other related
rights become exclusive ownership of the person who merged the code or in any other case the main developers.
  In order for a contribution to be accepted it has to obey the previously
established rules for contribution acceptance in cling's work flow and rules.